RESUMEN
We provide the first continuous Indian Summer Monsoon (ISM) climate record for the higher Himalayas (Kedarnath, India) by analyzing a 14C-dated peat sequence covering the last ~8000 years, with ~50 years temporal resolution. The ISM variability inferred using various proxies reveal striking similarity with the Greenland ice core (GISP2) temperature record and rapid denitrification changes recorded in the sediments off Peru. The Kedarnath record provides compelling evidence for a reorganization of the global climate system taking place at ~5.5 ka BP possibly after sea level stabilization and the advent of inter-annual climate variability governed by the modern ENSO phenomenon. The ISM record also captures warm-wet and cold-dry conditions during the Medieval Climate Anomaly and Little Ice Age, respectively.
RESUMEN
In recent years group III nitrides have gained recognition as being the most important materials for optoelectronics and electronics applications. The zinc-blende modification of GaN and AlN is receiving much attention over their wurtzite structure. Our present work deals with the detailed ab initio calculations of group III nitrides and phosphides in the zinc-blende phase. The plane wave pseudopotential approach is used to study the different properties of the material based on the concept of density functional theory (DFT). The converged plane wave cut-off energy (E(cut)) is used to set the number of plane waves, which varies from material to material. The calculated energy bandgaps are based on our theoretical equilibrium lattice constants. Our reported energy bandgap for InN (0.86 eV) is in good agreement with the recently reported experimental result (>0.7 eV and<1.0 eV).
